Anti-rust additive composition

ABSTRACT

Anti-rust additive composition: A. ALKANOLAMINE SALT OF FATTY ACID B. ALKANOLAMINE SALT OF AROMATIC ACID C. FREE ALKANOLAMINE D. SODIUM ALKYLBENZENE SULFONATE E. MINERAL OIL BASE

United States Patent [191 Marin et a1.

[ July 29, 1975 ANTI-RUST ADDlTIVE COMPOSITION lnventors: PierreDominique Marin, Rouen; Robert Tirtiaux, Mont Saint-Aignan, both ofFrance Assignee: Exxon Research and Engineering Company, Linden, NJ.

Filed: May 29, 1974 Appl. No.: 474,257

Foreign Application Priority Data May 29, 1973 U.S. Cl. 252/33.3; 44/66;44/71; 252/34; 252/34.7; 252/51.5 R; 252/389 R; 252/392; 72/42 Int. Cl.C10m 1/32;C10m 3/26 Field of Search 252/33.3, 34, 34.7, 51.5 R, 252/392,389 R; 44/66, 71; 72/42 References Cited UNITED STATES PATENTS PrimaryExaminer-Delbert E. Gantz France 73.19388 6/1950 Lieber 252/392Assistant Examinerl. Vaughn Attorney, Agent, or Firm-Frank T. Johmann[57] ABSTRACT Anti-rust additive composition:

a. alkanolamine salt of fatty acid b. alkanolamine salt of aromatic acidc. free alkanolamine d. sodium alkylbenzene sulfonate e. mineral oilbase 12 Claims, N0 Drawings ANTI-RUST ADDITIVE COMPOSITION The inventionrelates to an additive composition which is intended for use as ananti-rust agent in hydrocarbon-based compositions, for example petroleumoil compositions such as lubricants, liquid fuels and motor fuels; andmore especially in emulsifiable oils for metalworking, whether or notthose oils are hydrocarbon based. The invention further relates tocompositions, for example emulsifiable oils, containing the additive.

Quite often, liquid hydrocarbon-based compositions are brought intocontact with material made of iron, steel or cast iron, in the presenceof water. Thus. liquid fuels and motor fuels are stored in tankscontainers or holders, at the bottom of which there is always a certainquantity of water. Again, certain lubricants are used for lubricatingmechanism that is exposed to water. Additives are commonly embodied inall these various compositions for the purpose of preserving thematerial from rust.

p More especially, it is essential to incorporate an antirust additivein the emulsifiable oils which are used for machine metals. The properworkingof a machine tool, lathe, milling and planing machines etc,requires the tool to be lubricated and cooled by spraying on to it asuitable liquid. When the flow of heat liberated by the tool isconsiderable, the liquid used in an emulsion of oil in water, containingfrom 1 to 10% oil. As a rule, this emulsion is prepared in situ, in themachining shop, by diluting an. emulsifiable lubricating composition inwater. The emulsifiable lubricating composition must meet a certainnumber of requirements. ln particular, it must disperse spontaneouslyinwater and, form an emulsion which is stable and does not foam. It isimportant for it to preserve from corrosion both themachine and the toolas well as the part being machined. It is also very important thatfoaming during metal-working operationsis minimized, preferablyeliminated. ln practice these different requirements are difficult toreconcile.

Among the anti-corrosion agents normally included in-emulsifiable oils,the 'mostefficient are alkanolamides of low melting point, derived fromfatty acids. Unfortunately, these products drastically affect theemulsibility of the oil in water. Other known additives includealkanolamine fatty ester compounds, and salts formed by neutralizing anacid such as oleic acid with the equivalent quantity of an alkanolamine.However these types give rise to heavy foaming during their use in, forexample, cutting oils.

One object of the present invention is an anti-rust additive which isintended for use in hydrocarbon-based compositions and also for use inemulsifiable oils, whether they are hydrocarbon-based or, for'example,are based on synthetic lubricant compounds.

The invention also includes an emulsifiable oil containing such anadditive and, still further, an emulsion formed from such an oil.

According to the invention an anti-rust additive essentially comprises la. at least one salt of at least onealiphatiecarboxylic acid having 6 to20 carbon atoms per molecule and at where R is a hydroxyalkyl group andX and Y are the same or different groups'selected from hydrogemalkyl andhydroxyalkyl. v 1

The free alkanolamine is very preferably the same as that present in thesalt. When the additive contains several alkanolamines, a chemicalbalance is established spontaneously between the free alkanolaminesandthe alkanolamines contained in the salts.

lt willrbe seen that in the'additive according to the invention for eachequivalent of alkanolamine(s) incorporated with the acid(s) in thesalts, thereare from 0.5 to 2 equivalents offree-alkanolamine(s)present. Preferably there are l to 2, advantageously l to l .7equivalents of-free alkanolamine(s). 1 i

The alkanolamines can be primary, secondary and tertiary alkanolamines.having only one alcohol func-- tional group, forexample-monoethanolamine isopropanolamine. N-dimethylethanolamine, N-diethylethanolamine,' N-dimethylisopropanolamine andN-diethylisopropanolamine.

They can also be secondary or tertiary alkanolamines having two or threealcohol functional groups, forexample diethanolamine, N-methyldiethanolamine, .N-

ethyl diethanolamine and diisopropanolamine; triethanolamineandtriisopropanolamine. .1 a

Preferably a mixture of alkanolamines is present, for instance a mixtureof mono, di andtri-ethanolamine, or a mixture diandtri-isopropanolamine. Advantageously the mixture is ofdiisopropanolamine and triisopropanolamine.

The carboxylic acids are those whose molecule contains from 6 to 20carbon atoms, inclusive, preferably 10 to 20, advantageously 10 to l8.Suitable aliphatic acids are saturated acids, for example caprylic,decanoic, lauric, myristic, palmitic and stearic acids; or un--saturated acids, for example linoleic, linolenic, oleic andundecylenic'acids'A mixture of aliphatic acids may be used, for exampletall oil acids.

It was foundgthat the said aliphatic acid/alkanolamine salts tended toform gels when they were dispersed in a hydrocarbon oil. This drawbackis avoided, in accordance with the invention, by including said-aromaticacid/alkanolamine salts. The weight ratio (calculated as freeacids) ofaromatic acid to aliphatic acid ,is from 0.1,: l to 10": I

The aromatic acid is preferably a direct ringsubstituted compound, forexample benzoic acid or a naphthoic acid. The molecule of the aromaticacid may also containother functional groups, for example hydroxy,amino, amido, nitro, :alkoxy groups. For instance, hydroxybenzoic or anamino-benzoic acid may be used. The molecule of aromatic acid may alsocontain one or more lower alkyl groups, such as methyl, ethyl,isopropyl,-isobutyl, provided that the total numso that thegtemper-atureof reaction is less than 130C,

and very. desirably not vmore than 120C. From 100-l20C is usually'foundsuitable.

The additive of the present invention has several advantages over thealkanolamides generally used as antirust agents in emulsifiableoils..First of all, it is more effective. Moreover, contrary to theusual alkanolamides, it is not detrimental tothe emulsibility of theoils. Finally it has unexpected anti-foaming properties.

The invention also provides an anti-rust emulsifiable compositioncomprising the foregoing anti-rust additive and an emulsifying agent,forexample one or more sodium alkylbenzene sulphonates. In: addition thecmulsifiable compositionmay also contain a solubilizing agentforassisting'andstabilizing oil-in-wateremulsions formed from thecmulsifiable composition. Such an agent is, for examp1e,-butyl glycol orbutyl cellosolve.

The present invention also includes within its scope an'emulsifiable=oil whose properties are improved by the use of this additive. This oilcontains the usual constituents of cmulsifiable metal-working oilsult isbased on a mineral oil having a viscosity of 10 to 200 cSt at 50C. Thecmulsifiable oil contains emulsifiers in sufficient quantity'ito conferon it the desired emulsibility. This proportion is for preferencebetween 10 and by weight. The emulsifiers can be selected from the usualemulsifiers. lt is possible to use in particular soalkylbenzenesulphonates, sodium =alkyl sulphates-sodium salts of fatty acids. sodiumsalts of colophony, re'sinic acids. Use is made for preference of amixture of emulsifiers including an anionic emulsifier anda non-ionicemulsifier. I K

This cmulsifiable oil contains for preference up to 5% by weight of anextreme pressure lubricating agent of the-usualappropriate type. Itcontains advantageously up to 3% of a bactericidal agent. for instance aquaternary ammonium salt. lt is characterised essentially in thatincludes from 1 to 5% by weight of' the anti-rust agent of the presentinvention. I

lt suffices to dilute this oil with water to prepare an emulsion whichis suitable as a lubricant for metal working. The emulsion thusobtained. which may contain from I to for preference 1 to 10%, by volumeof the cmulsifiable oil defined above, is also included A mixture wasformed of the following:

I -Bcnzoic acid 13 parts by weight Laurie acid 1-1 "Diisopropanolamine38 Triisopropanolaminc 35 .This mixtureth'erefore contained 2.7equivalents of alkanolamines for every equivalent of the acids.

This mixture was melted by heating it to C 1 10C. lt was thn allowed tocool. The product obtained is one according to the invention and is anhomogeneous liquid'(Product A).

Example 2 A 'emulsifiable anti-rust oil (Hlwas obtained by adding 2parts by weight of product A as described in example 1, to IOO'parts byweight of an cmulsifiable oil (HO) whose composition was as follows:

Lubricant base 70% The lubricant base was a mineral oil of the spindleoil type. characterised by a viscosity of 13.3 cSt at 50C. By meredilution of oil H in water. in 1 vol% concentration, a lubricatingemulsion for metal-working was obtained.

The anti-rust properties'of this emulsion wereassessed by means of theHerbert test-(British Standard lP -63). hereafter called the 1Pperformance test. On a carefully cleaned grey cast iron plate wasarrangeda layer of steel shavings and on to them were poured a fewmillilitres of the emulsion being tested. 24 hours'later; the shavingswere removed and the surface of the plate'was examined.

It was found that the anti-wear agent according to the invention, addedin the proportion of 2% to the soluble oil. makes it possible to obtainthe complete protection of the metal from rust. v

Example 3 The same test was carried out as in Example 2, the product Abeing replaced by various commercial antirust additives bearing thereference B. C, D and E.

B and C are alkanolamides of oleic acid. D is a mixture of alkanolamidesobtained by condensing tall oil acids with diethanolamine. E is a saltformed by neutralizinga C oxoacid with one equivalent oftripropanolamine.

For each of these anti-rust additives the minimum proportion wasdetermined that has to be added to the said oil HO (EX. 1) to obtaincomplete protection of the metal from rust.

The following results were obtained:

ample.

Example '4 This example shows the anti-foaming properties of the productto which the invention refers. The emulsifiable anti-rust oil' H definedin Example 2- was diluted 5 vol% in water.

The emulsion thus obtained was subjected to the test which is describedin ASTM standard D-892. In a graduated 1000 ml. test-tube were placed190 ml. of the emulsion. The test-tube wasplaced in a bath kept at 24C.Glass was blown into the sample through a glass frit plate arranged atthe bottom of the test-tube. After 5 minutes the blowing in of air wasstopped and the volume. of froth formed was at once noted. Finally.minutes later, the volume of froth still remaining was noted.

The same test was repeated, replacing the 2 vol.% A in'the soluble oilHO (EX. 2) by 2 vol.% of the commercial product B (see-EX. 3). The testwas further repeated with 5 vol% of A and also with 5 vol.% of productsB, C, D, and E (see EX. 3) and F, an amine dioleate ester. The test wasagain repeated employing A at 5 vol% but changing the alkanolamine (G to.l).

The following results were obtained:

It is clear that the additives according to the invention (A and G to J)endowed the emulsions with very superior anti-foaming properties.

Example 5 To prepare another anti-rust additive and according to theinvention, the following were mixed together:

16 parts by weight of para-aminobenzoic acid.

16 parts by weight of n-decanoic acid 69 parts by weight oftriethanolamine This mixture therefore contained 2.5 equivalents oftriethanolamine to each equivalent of the acids. The mixture was meltedby heating it to about 1 10C, and then it was allowed to cool. Theproduct obtained was a homogeneous liquid.

Example 6 Additives were made by forming salts of various carboxylicacids (l mole) with triethanolamine (T.E.A.) 3 M7: of each additive wasadded to the oil composition HO (see EX. 2). The appearance of the finalmix was observed. 5 ml. of the final mix was then added to 95 ml. ofwater in a stoppered 100 ml. pyrex cylinder and the cylinder rotated.The time taken for complete emulsion to form was noted the emulsibilitytime. The IP performance test results (See Ex. 2) were also obtained foreach sample.

The results are tabulated below:

It can be seen that only the additive according to the invention (thelast one in the table) enables a clear oil composition to be obtainedcoupled with short emulsibility time and acceptable l.P. performanceresults.

Example 7 Various additives were prepared and incorporated into the oilcomposition HO (see Ex. 2). The IP test (see Ex. 2) was conducted andthe results tabulated. The table shows firstly the results with a seriesof salts using both benzoic and lauric acids and secondly using onlybenzoic acid and only laurie acid.

MOLAR RATIO triethanolamine 1P Performance henzoic lauric (mininumemulsion (0.7 mole )+(0.3 mole) "i to pass test) 1.0} only lauric acid1.5 2.0 present 1.5

2.0 only benzoic acid present .5

The results show the critical nature of the alkanolamine acid ratio.There is a rapid and marked increase in IP Performance in the molarratio range 1.5 l to 3.0 I, particularly 1.5 l to 2.7 1. Above a ratioof 3 1 there is a rapid decrease in performance.

Although lauric acid alone gives adequate 1P results it has otherproperties which are disadvantageous Vide Ex. 6 on appearance andemulsibility time.

The foregoing examples show that the anti-rust agent forming the objectof the invention is particularly suitable for cmulsifiable metal-workingoils. Nevertheless, this anti-rust agent can be used in otherapplications. Generally speaking, it can be incorporated advantageouslyin hydrocarbon compositions that are stored or used in contact with acertain quantity of water. For instance, it can be incorporated withfuels of liquid type or motor fuels. It is also possible to embody it inthe composition of certain lubricating greases, in lubricating oils forsteam engines, in turbine lubricating oils etc.

We claim:

' 1. An anti-rust additive composition comprising:

a. at least one salt of at least one aliphatic carboxylic acid having 6to 20 carbon atoms per molecule and at least one alkanolamine.

b. at least one salt of at least one aromatic carhoxylic acid having upto 20 carbon atoms per molecule and at least one alkanolamine. theweight ratio. calculated as free acid, of aromatic acid to aliphaticacid being 0.1 l to 10: l. and

c. at least one alkanolamine in the free state so that,

in total, there are 1.5 to 3.0 equivalents of alkanolamine present perequivalent of acid; the alkanolamines being compounds containing up tocarbon atoms per molecule and having the formula a hydroxyalkyl groupand X and Y are the same or different groups selected from hydrogen,alkyl and hydroxyalkyl.

2. A composition as claimed in claim I, wherein acids.

6. A composition as claimed in claim 1, wherein the aromatic acid isbenzoic acid or p-aminobenzoic acid.

7. A composition as claimed in claim 1. wherein the alkanolamine isselected from monoethanolamine, isopropanolamine,N-dimethylethanolamine, N- diethylethanolamine, N-dimethylisopropanolamine, N-diethylisopropanolamine. diisopropanolamine.triisopropanolamine. diethanolamine. N- methyldiethanolamine andN-ethyldiethanolamine.

8. A composition as claimed in claim 7, wherein the alkanolaminesconsist of a mixture of at least two alkanolamines selected fromethanolamine. diethanolamine and triethanolamine 9. A compositionasclaimed in claim 7,-wherein the alkanolamines consist of a mixture of atleast two alkanolamines selected from isopropanolamine,diisopropanolamine and triisopropanolamine.

10. A composition as claimed in claim. 1, obtained by neutralising at atemperature below 1309C l part by weight of one or more said carboxylicaliphatic acids and 0.l to 10 parts by weight of one or more saidaromatic carboxylic acids, with from 1.5 to 3.0 equivalents in totalofthe alkanolamine per equivalent in total of the acids.

11. An emulsifiable composition comprising a composition as claimed inclaim 1. further containing a dium alkylbenzene sulphonate emulsifyingagent. j

12. The composition of claim 11, further containing a mineral oil basehaving a viscosity of ID to 200 est at 50C, and wherein the amount ofthe emulsifier is from 10 to 30 weight percent and the amount of theanti-rust additive composition is from 1 to 5 weight'percent.

1. AN ANTI-ADDITIVE COMPOSITION COMPRISING: A. AT LEAST ONE SALT OF AT LEAST ONE ALIPHATIC CARBOXYLIC ACID HAVING 6 TO 20 CARBON ATOMS PER MOLECULE AND AT LEAST ONE ALKANOLAMINE, B. AT LEAST ONE SALT OF AT LEAST ONE AROMATIC CARBOXYLIC ACID HAVING UP TO 20 CARBON ATOMS PER MOLECULE AND AT LEAST ONE ALKANOLAMINE THE WEIGHT RATIO CALCULATED AS FREE ACID OF AROMATIC ACID ALIPHATIC ACID BEING 0.1: 1 TO 10 :1 AND C. AT LEAST ONE ALKANOLAMINE IN THE FREE STATE SO THAT IN TOTAL THERE ARE 1.5 TO 3.0 EQUIVALENTS OF ALKANOLAMINE PRESENT PER EQUIVALENT OF ACID, THE ALKANOLAMINES BEING COMPOUNDS CONTAINING UP TO 20 CARBON ATOMS PER MOLECULE AND HAVING THE FORMULA
 2. A composition as claimed in claim 1, wherein there are 2.0 to 3.0 equivalents of alkanolamine per equivalent of acid.
 3. A composition as claimed in claim 1, wherein the free alkanolamine and alkanolamine present in the salts are the same.
 4. A composition as claimed in claim 1, wherein the aliphatic acid is selected from those having 10 to 18 carbon atoms per molecule.
 5. A composition as claimed in claim 4, wherein the acid is selected from lauric, palmitic, oleic and tall oil acids.
 6. A composition as claimed in claim 1, wherein the aromatic acid is benzoic acid or p-aminobenzoic acid.
 7. A composition as claimed in claim 1, wherein the alkanolamine is selected from monoethanolamine, isopropanolamine, N-dimethylethanolamine, N-diethylethanolamine, N-dimethyl isopropanolamine, N-diethylisopropanolamine, diisopropanolamine, triisopropanolamine, diethanolamine, N-methyldiethanolamine and N-ethyldiethanolamine.
 8. A composition as claimed in claim 7, wherein the alkanolamines consist of a mixture of at least two alkanolamines selected from ethanolamine, diethanolamine and triethanolamine.
 9. A composition as claimed in claim 7, wherein the alkanolamines consist of a mixture of at least two alkanolamines selected from isopropanolamine, diisopropanolamine and triisopropanolamine.
 10. A composition as claimed in claim 1, obtained by neutralising at a temperature below 130*C 1 part by weight of one or more said carboxylic aliphatic acids and 0.1 to 10 parts by weight of one or more said aromatic carboxylic acids, with from 1.5 to 3.0 equivalents in total of the alkanolamine per equivalent in total of the acids.
 11. AN EMULSIFIABLE COMPOSITION COMPRISING A COMPOSITION AS CLAIMED IN CLAIM 1 FURTHER CONTAINING A SODIUM ALKYLBENZENE SULPHONATE EMULSIFYING AGENT. 12, THE COMPOSITION OF CLAIM 11 FURTHER CONTAINING A MINERAL OIL BASE HAVING A VISCOSITY OF 10 TO 200 CST AT 50*C AND WHEREIN THE AMOUNT OF THE EMULSIFIER IS FROM 10 TO 30 WEIGHT PERCENT AND THE AMOUNT OF THE ANTI-RUST ADDITIVE COMPOSITION IS FROM 1 TO 5 WEIGHT PERCENT. 